Study on characteristics and sintering behavior of W-Ni-Co tungsten heavy alloy by a secondary ball milling method

W-7Ni-3Co heavy tungsten alloys fabricated by mechanical alloying have been investigated. Characteristics and sintering behavior of the model alloys are strongly influenced by different milling methods. In this study, a pre-milled binder phase of γ(Ni,Co) was synthesized by a secondary ball milling method. Therefore, the microstructure and the solubility of the tungsten grain and the γ(Ni,Co) binder phase can be altered in the alloy system. The results suggest that the use of the secondary ball milling promotes the formation of solid phase during sintering. A microstructure composed of the fine and uniformly distributed γ(Ni,Co) binder phase with a large amount of twinned structures was obtained, which can be related to an increase of mechanical properties.